Heat exchanger



June 2, 1964 A. G. BUTT ETAL HEAT EXCHANGER Filed March '7, 1960 INVENTORS ALAN e. BUTT LEWIS J. 0500 BY V Q 4 ATTORNEYS United States Patent O 3,135,321 HEAT EXCHANGER Alan G. Butt and Lewis .1. Dedo, La Crosse, Wis,

assignors to The Trane Company, La Crosse, Wis, a corporation of Wisconsin Filed Mar. 7, 1960, Ser. No. 13,098 SClaims. (Cl. 165-154) This invention relates to heat exchangers and more particularly to a heat exchanger hermetically sealing and enclosing equipment to be cooled.

The device is particularly adapted for cooling electronic equipment which must operate in rarefied atmospheres. It is, therefore, desirable and often necessary that the pressure of air in the equipment space be maintained at a higher level than that of the ambient air.

It is an object of this invention to provide an inner container for housing the equipment, a sealed intermediate container enclosing said inner container, an outer container enclosing said intermediate container, heat transfer fins extending from the intermediate container to the inner container and heat transfer fins extending from the intermediate container to the outer container, with the heat transfer fins integrally joined to the containers to provide a strong unitary wall.

It is an object of this invention to provide a first container for housing equipment and a second container enclosing but being spaced from the first container to provide passageways therebetween and openings in the first container for movement of fluid from the first container into the passageways and other openings in the first container for movement of fluid from the passageways back to the first container.

It is another object of the invention to provide means for cooling a sealed first container comprising an outer casing which houses, but is spaced from the first container to provide pasasgeways therebetween, heat transfer elements in the passageways and openings in the second container for the movement of cooling fluid into and out of the passageways.

In is another object of the invention to provide an inner tapered container, an intermediate tapered container housing the inner container, an outer tapered container housing the intermediate container, heat transfer fins between the containers whereby the inner casing may be forced into the intermediate container and the intermediate container may be forced into the outer container to force the heat transfer fins into contact with the containers.

Other objects and advantages of the invention will become apparent as the specification proceeds to describe the apparatus with reference to the accompanying drawings in which:

FIG. 1 is a side elevational view of the changer;

FIG. 2 is a top view of the heat exchanger;

FIG. 3 is a perspective view in cross-section on line 3-3 of FIG. 1 with some parts in exploded position to more clearly show the interior construction; and

FIG. 4 is a perspective view on an enlarged scale showheat exing the fin and the upper portion of the outer casing.

\ Referring to FIGS. 13,' the heat exchanger has an inner container 10, an intermediate container 12, and an outer container 14. Mounting posts 16 extend through and are brazed to the bottom ends of containers 10, 12, and 14. Equipment to be cooled which is in the inner container is supported on the inner ends of posts 16. The outer ends of the posts 16 are adapted to be secured to a support (not shown).

The outer container 14 has a hole 18 adapted to be connected to the suction of a fan (not shown). Air or other cooling fluid is drawn in through holes 20 in the outer container 14 and flows in the passageways between the sides of containers 12 and 14. Corrugated heat transfer fin material 22 extends between and is brazed to the sides of the containers 12 and 14. In the space between the bottom end wall of the container 12 and the bottom end wall of the container 14 are corrugated distributor heat transfer fins 24 and 26. These fins provide substantially uniform flow of fluid in the passageways between the containers 12 and 14 in addition to transferring heat from the end wall of container 12 to the fluid flowing in the passageways. i

The end wall of the container 10 has a hole 28 which is adapted to be connected to the discharge of a fan which is part of the equipment (not shown) mounted in the container 10. Corrugated distributor heat transfer fins 30 are mounted in the space between the end wall of container 1t) and the end wall of container 12. Pins 30 are arranged in the same manner as fins 24 and 26. Heat transfer fins 32 are mounted in the spaces between the side walls of the containers 10 and 12. Holes 34 in the inner container 10 provide for the flow of air into the container 10 from the passageways between the containers 10 and 12. v

The distributor heat transfer fins 30 distribute the air or gas flowing from the hole 28 substantially uniformly to the space between the four side walls of the containers 10 and 12. In like manner, the distributor fins 24 and 26 provide flow conditions by which .uniform flow is obtained in the space between the four side walls of the con.-

tainers 12 and 14.

The container 12 has an outwardly extending flange 36 which is brazed or welded to a clamping ring 38. The top edge of the container 10 is brazed or welded to the clamping ring 38, and the top edge of the container 14 is brazed or welded to the lower surface of the flange 36.

On O-ring sealing member 40 of resilient material such as neoprene is mounted in a groove in the top of the clamping ring 38 and provides a seal between the clamping ring 38 and the cover 42. Bolts 44 extend through the cover 42 into threaded engagement with the clamping ring 38 to hold the cover 42 against the clamping ring 38 with the O-ring 40 in compressed condition to effect a seal.

In FIG. 1, the angle of taper of the side walls is indicated by numeral 46.

The method of assembling and brazing the heat exchanger will now be described. Because of the construction of the heat exchanger, the fixture for holding the their final relative positions. The sides of the containers.

elements in position for brazing can be relatively simple. The parts may be assembled by first placing the container 14 and the posts 16 in the fixture. Rings of brazing material (not shown) are placed over the posts 16 so that the rings rest upon the inside surface of the bottom of container 14. Distributor heat transfer fins 24 and 26 are now placed on the bottom of the outer container 14.

The intermediate container 12 with the fins 22 wrapped around its sides is now inserted in the outer container 14. The distributor heat transfer fins 30 are then placed on the bottom of the intermediate container 12. Rings of brazing material (not shown) are placed on the posts 16 so that the rings rest upon the inside surface of the bottom of container 12.

The inner container 10 with the heat transfer fins 32 wrapped around its sides is now inserted in the intermediate container 12. Rings of brazing material (not shown) are placed on the posts 16 so that the rings rest upon the inside surface of the bottom of container 10.

The tapered containers 1t 12, and 14 and the heat transfer fins 22 and 32 are sized so that pressure contact between these parts is established before the parts are in 10, 12, and 14 are tapered as indicated by numeral 46 in FIG. 1. Therefore, as the containers are forced into their final relative positions, the heat transfer fins 22 and Patented June 2., 1964 32 are compressed to insure that good brazing contact is obtained. It-should also be understoodthat container 12 is forced into container 14 until fins 24 and 26 are compressed for contact with the bottoms of containers 12 and 14, and in like manner container 10 is forced into container 12 until fins 30 are compressed for contact with the bottoms of containers l and 12. The fixture holds the containers 1t 12, and 14 in such positions that the upper edge of container 19 is in line with the upper surface of flange 36 of container 12 and the upper edge of container'14 is in contact with the lower surface of flange 36. The fins 22, 24, 26, 30, and 32 have on each face a thin layer of metal which has a lower melting tempera ture than that of the base metal of the fins. The brazing rings also have a lower melting temperature than the other parts.

The assembly may be brazed in any suitable manner. For instance, when the parts are of aluminum, the assembly may be brazed by immersing in a salt bath to raise the temperature to the point at which the brazing rings and the brazing alloy on the surfaces of the fins melts and integrally joins the parts. The clamping ring 38 may then be hand brazed or welded to the containers 10, 12, and 14.

It is thus seen that the structure in which the fins are integrally joined to the containers provides high heat transfer capacity in a small space as well as providing structural strength to resist deformation dueto the internal pressure. 7

Although the heat exchanger has been shown as substantially rectangular in cross-section, because this shape permits stacking several heat exchangers in a minimum space, the heat exchanger can be circular or substantially circular in cross section, if desired. 7

Although we have shown a specific embodiment of our invention, We contemplate that changes may be made to outer surfaces of walls of said first container, said first heat transfer fins being integrally joined to inner surfaces of the walls of said second container to provide first fluid vwithout departing from the scope or spirit of our invenpassageways between walls of said first and second containers, said firstcontainer having a first openng for the flow of fluid from the first container to said first fluid passageways, said first container having a second opening for the flow of fluid from said first fluid passageways to said first container, a third container surrounding said second container, second heat transfer fins integrally joined to the outer surfaces of walls of said second container, said second heat transfer fins being integrally joined to the inner surfaces of walls of said third container to provide second fluid passageways between walls of said second and third containers, said third container having a first opening for the flow of fluid into said third container, said third container having a second opening for the flow of fluid out from said third container, and means hermetically sealing said second container.

2. A heat exchanger comprising a first container for equipment to be cooled, a second container surrounding said first container, first heat transfer fins integrally joined to outer surfaces of walls of said first container, said first heat transferfins being integrally joined to inner surfaces of the walls of said second container to provide first fluid passageways between walls of said first and second containers, said first container having a first opening for the flow of fluid from the first container to said first fluid passageways, said first container having a second opening for the flow of fluid from said first fluid passageways to said first container, a third container surrounding said second container, second heat transfer fins integrally joined to the outer surfaces of walls of said second con- A tainer, said second heat transfer fins being integrally joined to the inner surfaces of walls of said third container to provide second fluid passageways between walls of said second and third containers, said third container having a first opening for thetlow of fluid into said third container, said third container" having a second opening for the flow of fluid out from said third container, a

clamping ring, said first, said second, and said third container each having open ends, means integrally joining the open ends of said first, said second and saidthird containers to said clamping ring, and a cover in hermetic closing sealing engagement with said clamping ring! 3. A heat exchanger comprising a first container having a bottom wall and upwardly diverging substantially planar side walls, said first container being adapted to 1 enclose equipment to be cooled, a secondcontainer surrounding said first container, said second container having a bottom wall and upwardly diverging substantially planar side walls, first heat transfer fins contacting the outer surfaces of the side walls of said first container; said first heat transfer fins contacting the inner surfaces of the side walls of said secondcontainer to provide first fluid passageways between the side walls of said first and second containers, said first container having a first open ing for the flow of fluid from the first container to said first fluid passageways, said first container having a second opening for the flow of fluid from said first fluid passageways to said first container, a third container surrounding said second container, said third container having albottom wall and upwardly diverging substantially planar side walls, second heat transfer fins contacting the outer surfaces'of the side walls of said second container, said second heat transfer fins contacting the inner surfaces of the side walls of said third container to provide second fluid passageways between the side walls of said second and third containers, said third container having'a first opening for the flow of fluid into said third container, said third container having a second opening for the flow of fluid out from said third container, said first, second, and third containers being sized to compress said fins when in assembled operative positions.

4. A heat exchanger comprising a first container having a bottom wall and substantially planar side walls, said first container being adapted to enclose equipment to be cooled, a second container surrounding said first container, said second container having a bottom wall andsubstantially planar side walls, first heat transfer fins contacting the outer surfaces of the bottom wall and side walls of said first'container, said first heat transfer fins contacting the inner surfaces of the bottom 'Wall and side walls of said second container to provide first fluid passageways between the bottom walls and the side Walls of said first and second containers, said first container having openings for the flow of fluid between said first container and said first fluid passageways, a third container surrounding said second container, said third container having a bottom wall and side walls, second heat transfer fins contacting the outer surfaces of the side walls of said second container, said second heat transfer fins contacting the inner surfaces of the side walls of said third container to provide second fluid passageways between the side walls of said second containerand said third container, and openings in said third container in" fluid communication with said second fluid passageways for conducting fluid to and from said second fluid passage ways.

5. A heat exchanger comprising a first container havingfluid passageways between the bottom walls and the 5 side walls of said first and second containers, said first container having openings for the flow of fluid between said first container and said first fluid passageways, a third container surrounding said second container, said third container having a bottom wall and side walls, second heat transfer fins contacting the outer surfaces of the bottom wall and side walls of said second container, said second heat transfer fins contacting the inner surfaces of the bottom Wall and side Walls of said third container to provide second fluid passageways between the bottom walls and the side walls of said second and third containers, and openings in said third container in fluid communication with said second fluid passageways for conducting fluid to and from said second fluid passageways.

References Cited in the file of this patent UNITED STATES PATENTS 1,639,051 Munday Aug. 16, 1927 2,362,044 Blancha Nov. 7, 1944 2,445,582 Melville July 20, 1948 2,654,583 Treanor Oct. 6, 1953 2,791,621 Hewitt et a1 May 7, 1957 2,820,616 Nabal et al Jan. 21, 1958 2,893,704 Passman July 7, 1959 2,905,742 Woods Sept. 22, 1959 2,941,123 Grebe June 14, 1960 

1. A HEAT EXCHANGER COMPRISING A FIRST CONTAINER FOR EQUIPMENT TO BE COOLED, A SECOND CONTAINER SURROUNDING SAID FIRST CONTAINER, FIRST HEAT TRANSFER FINS INTEGRALLY JOINED TO OUTER SURFACES OF WALLS OF SAID FIRST CONTAINER, SAID FIRST HEAT TRANSFER FINS BEING INTEGRALLY JOINED TO INNER SURFACES OF THE WALLS OF SAID SECOND CONTAINER TO PROVIDE FIRST FLUID PASSAGEWAYS BETWEEN WALLS OF SAID FIRST AND SECOND CONTAINERS, SAID FIRST CONTAINER HAVING A FIRST OPENING FOR THE FLOW OF FLUID FROM THE FIRST CONTAINER TO SAID FIRST FLUID PASSAGEWAYS, SAID FIRST CONTAINER HAVING A SECOND OPENING FOR THE FLOW OF FLUID FROM SAID FIRST FLUID PASSAGEWAYS TO SAID FIRST CONTAINER, A THIRD CONTAINER SURROUNDING SAID SECOND CONTAINER, SECOND HEAT TRANSFER FINS INTEGRALLY JOINED TO THE OUTER, SURFACES OF WALLS OF SAID SECOND CONTAINER, SAID SECOND HEAT TRANSFER FINS BEING INTEGRALLY JOINED TO THE INNER SURFACES OF WALLS OF SAID THIRD CONTAINER TO PROVIDE SECOND FLUID PASSAGEWAYS BETWEEN WALLS OF SAID SECOND AND THIRD CONTAINERS, SAID THIRD CONTAINER HAVING A FIRST OPENING FOR THE FLOW OF FLUID INTO SAID THIRD CONTAINER, SAID THIRD CONTAINER HAVING A SECOND OPENING FOR THE FLOW OF FLUID OUT FROM SAID THIRD CONTAINER, AND MEANS HERMETICALLY SEALING SAID SECOND CONTAINER. 